/*
 * Copyright 2014 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.util.concurrent;

import io.netty.util.internal.InternalThreadLocalMap;
import io.netty.util.internal.UnstableApi;

/**
 * A special {@link Thread} that provides fast access to {@link FastThreadLocal} variables.
 */
public class FastThreadLocalThread extends Thread {

  // This will be set to true if we have a chance to wrap the Runnable.
  private final boolean cleanupFastThreadLocals;

  private InternalThreadLocalMap threadLocalMap;

  public FastThreadLocalThread() {
    cleanupFastThreadLocals = false;
  }

  public FastThreadLocalThread(Runnable target) {
    super(FastThreadLocalRunnable.wrap(target));
    cleanupFastThreadLocals = true;
  }

  public FastThreadLocalThread(ThreadGroup group, Runnable target) {
    super(group, FastThreadLocalRunnable.wrap(target));
    cleanupFastThreadLocals = true;
  }

  public FastThreadLocalThread(String name) {
    super(name);
    cleanupFastThreadLocals = false;
  }

  public FastThreadLocalThread(ThreadGroup group, String name) {
    super(group, name);
    cleanupFastThreadLocals = false;
  }

  public FastThreadLocalThread(Runnable target, String name) {
    super(FastThreadLocalRunnable.wrap(target), name);
    cleanupFastThreadLocals = true;
  }

  public FastThreadLocalThread(ThreadGroup group, Runnable target, String name) {
    super(group, FastThreadLocalRunnable.wrap(target), name);
    cleanupFastThreadLocals = true;
  }

  public FastThreadLocalThread(ThreadGroup group, Runnable target, String name, long stackSize) {
    super(group, FastThreadLocalRunnable.wrap(target), name, stackSize);
    cleanupFastThreadLocals = true;
  }

  /**
   * Returns the internal data structure that keeps the thread-local variables bound to this thread.
   * Note that this method is for internal use only, and thus is subject to change at any time.
   */
  public final InternalThreadLocalMap threadLocalMap() {
    return threadLocalMap;
  }

  /**
   * Sets the internal data structure that keeps the thread-local variables bound to this thread.
   * Note that this method is for internal use only, and thus is subject to change at any time.
   */
  public final void setThreadLocalMap(InternalThreadLocalMap threadLocalMap) {
    this.threadLocalMap = threadLocalMap;
  }

  /**
   * Returns {@code true} if {@link FastThreadLocal#removeAll()} will be called once {@link #run()}
   * completes.
   */
  @UnstableApi
  public boolean willCleanupFastThreadLocals() {
    return cleanupFastThreadLocals;
  }

  /**
   * Returns {@code true} if {@link FastThreadLocal#removeAll()} will be called once {@link
   * Thread#run()} completes.
   */
  @UnstableApi
  public static boolean willCleanupFastThreadLocals(Thread thread) {
    return thread instanceof FastThreadLocalThread &&
        ((FastThreadLocalThread) thread).willCleanupFastThreadLocals();
  }
}
